398 Mr Willey, Some Zoological Results of a [Feb. 7, 



Monday, 7 February, 1898. 

 Mr F. Darwin, President, in the Chair. 

 The following were elected Fellows of the Society : 



J. H. C. Dalton, M.D., Trinity College. 

 A. H. Ramsey, M.A., Magdalene College. 

 W. M. Fletcher, B.A., Trinity College. 



The following communication was made to the Society : — 



Some Zoological Results of a Voyage to Melanesia during the 

 years 1894 — 1897. By Arthur Willey, D.Sc, Balfour Student. 



1. Nautilus. 1. The deposited eggs of N. pompilms were 

 obtained by me during the months July — September, 1897, in 

 cages kept at a depth of some 50 to 60 fathoms in Blanche Bay, 

 New Britain. They differ very slightly in the ornamentation of 

 the outer capsule from the eggs of N. macromphalus, the pectinate 

 ridges in those of the former species being more frill-like. 



2. The otolithic contents of the otocysts of Nautilus were 

 correctly described by Macdonald 1 in 1855 as consisting of in- 

 numerable minute otocones. Sometimes in preserved specimens 

 the effect of the preservation appears to be to coagulate the fluid 

 contents of the otocyst, so that the otocones cohere to form a 

 solid otolith. This explanation will account for the erroneous 

 interpretation recently published on this subject 2 . 



3. The region of the mantle which secretes the calcareous 

 septa of the shell is marked off from the surrounding region by 

 a thickened rim or contour line. The latter was described by me 

 under the name of the septal contour and figured on p. 170 of the 

 Quart. Journ. Micro. Sc, Vol. xxxix., 1896, together with a repre- 

 sentation of the pallio-septal arteries. The septal contour has 

 been redescribed by L. E. Griffin (loc. cit.) as the "posterior 

 ventral aponeurotic band" without referring to my account, al- 

 though the paper containing it is included in his bibliography. 



4. The animal of N. umbilicatus has not, so far as I am 

 aware, ever been examined or even seen by a zoologist before. 

 I was fortunate enough to obtain one specimen which had been 

 taken from the surface in the neighbourhood of the D'Entre- 



1 Phil. Trans. 1855, p. 277. Macdonald supposed his specimen, which was 

 obtained off the Isle of Pines, to be N. umbilicatus; but that it was really N. 

 macromphalus is abundantly evident from his description of the animal even if it 

 were not already known that he had mistaken the species. 



2 L. E. Griffin, "Notes on the Anatomy of Nautilus pompilius," Zool. Bulletin, 

 Vol. i. p. 147. 1897. 



